This invention pertains to a backlightable knob, as for automotive use, of a type wherein an indicator exhibits one color, such as white, in ambient light and wherein the indicator indicates a contrasting color when backlighted via a light pipe. This invention contemplates that the indicator and the light pipe are molded simultaneously so as to be intimately bonded to each other.
As exemplified in U.S. Pat. No. 5,359,165, it is known for such a knob to employ a light pipe, an outer end of which is flush with an outer wall. This patent discloses a method of making the knob wherein the light pipe is positioned as an insert in a mold wherein opaque material is molded over the light pipe.
As exemplified in U.S. Pat. Nos. 5,752,759, 6,003,206, and 6,019,478, in which the indicator is called a jewel and in which the light pipe is called a jewel holder, and as exemplified in U.S. Pat. No. 5,845,365, it is known for an indicator to exhibit one color, such as white, in ambient light, and to exhibit a contrasting color when backlighted via a light pipe.
U.S. Pat. No. 5,050,269, U.S. Pat. No. 5,450,653, and U.S. Pat. No. 5,688,461 provide further background of this invention.
This invention provides an improvement in a backlightable knob of the type noted above. Moreover, this invention provides a method for making such a knob, as improved.
The backlightable knob comprises a translucent structure, which comprises an indicator and a light pipe. The indicator is molded from a polymeric material, which is translucent and which exhibits a light color in ambient light, the light pipe is molded from a polymeric material, which is translucent and which is tinted so as to cause the indicator to exhibit a color contrasting with the light color when the light pipe is backlighted. This invention contemplates that the indicator and the light pipe are molded simultaneously so as to be intimately bonded to each another.
Preferably, the backlightable knob further comprises a polymeric body, which comprises a front wall and a central hub, wherein the front wall and the central hub are molded simultaneously. Preferably, moreover, the front wall has an outer face and has an aperture, through which the translucent structure extends so as to expose the indicator at the outer face.
In a preferred embodiment, the front wall and the central hub are molded simultaneously and unitarily. In the preferred embodiment, moreover, the front wall is molded around the translucent structure so as to cause the front wall and the translucent structure to be intimately bonded to each other.
In the preferred embodiment, furthermore, the backlightable knob further comprises an outer cover, which has an outer face and which is molded from a polymeric material so as to cover the outer face of the front wall of the polymeric body, except that the outer cover has an aperture, through which the indicator remains exposed.